1. Field of the Invention
The present invention relates to a navigation system for searching for an optimum route with considering weather information.
2. Description of Related Art
A navigation system is a device for searching for a route satisfying a search condition and for displaying the route on a map. As the search condition, there is such a condition as searching for the shortest route in distance or in time from the current position to the destination.
When the retrieved route is under bad weather, it will impose heavy strain on a driver. To remove the strain of the driver as much as possible, Japanese patent application laid-open No. 8-210865/1996 discloses a technique for searching for a route in a better weather condition with considering weather information.
Although the conventional navigation system with the foregoing configuration can inform the driver of the route in the better weather condition, it does not search for the route with considering vehicle information on the vehicle itself. Accordingly, it is not unlikely that the route in the better weather condition is impassable to the vehicle, which presents a problem of possibly informing the driver of an impassable route.
The present invention is implemented to solve the foregoing problem. Therefore, it is an object of the present invention to provide a navigation system capable of informing a driver of a route positively passable to the vehicle.
A navigation system according to the present invention searches for a route from a present position to a destination with taking account of the weather information collected by information collecting means and the vehicle information input by information input means.
This offers an advantage of being able to inform a driver of a route positively passable to the vehicle.
The navigation system according the present invention may collect regulation information on a road besides the weather information, and search for the route with considering the regulation information.
This offers an advantage of being able to inform the driver of a route more positively passable to the vehicle.
The navigation system according to the present invention may search for another route if the retrieved route is probably impassable to the vehicle even though the route satisfies a search condition.
This offers an advantage of being able to inform the driver of a detour if the route satisfying the search condition is under a snow chain warning or the like because of a snowfall on the route.
The navigation system according to the present invention may search for the route with considering a time period taken to mount snow chains on tires if the vehicle carries the snow chains, but is not yet equipped with the snow chains, when the route includes a road under snow chain warning.
This offers an advantage of being able to improve the accuracy of the route searching when the search for a shortest time route is set as the search condition because the accuracy of estimated arrival time is improved.
The navigation system according to the present invention may make a presentation, when the route searching mean retrieves another route, that the another route is a roundabout route.
This offers an advantage of being able to make the driver recognize that the retrieved route is a roundabout route.
The navigation system according to the present invention may provide, when the route retrieved by the route searching mean includes a road under regulation, regulation information about the road.
This offers an advantage of being able to make the driver recognize that he or she will meet a snow chain warning or the like when taking the retrieved route.
The navigation system according to the present invention may put weather marks on pass points on the route retrieved by the route searching mean by referring to weather information collected by the information collecting means.
This offers an advantage of being able to inform the driver of the weather condition of the retrieved route.
The navigation system according to the present invention may estimate passing time at the pass points, and put the weather marks at the passing time.
This offers-an advantage of being able to inform the drier of the weather condition at the passing.
The navigation system according to the present invention may make a decision as to whether maintenance of the vehicle is necessary or not from the vehicle information input by the information input means, or from information collected by a sensor mounted on the vehicle, and exhibit information indicating need of the maintenance when it is necessary.
This offers an advantage of being able to make the driver recognize that the maintenance of the vehicle is needed.
The navigation system according to the present invention may exhibit, when the route retrieved by the route searching mean includes a toll road, a toll on the vehicle by referring to the vehicle information input by the information input means.
This offers an advantage of being able to inform the driver of the toll.
The navigation system according to the present invention may refer to the vehicle information input by the information input means when exhibiting the route retrieved by the route searching mean, make a decision as to whether a parking lot at the destination is available for the vehicle, and halt informing the parking lot when the parking lot is unavailable for the vehicle.
This offers an advantage of being able to prevent the vehicle from going to unavailable parking lot.